Get an online Stockfish FEN evaluation in seconds: paste any position and chess.rodeo returns the evaluation, the best move, and the full line — free, no signup.
Stockfish Evaluation for Any FEN, Online
Paste a FEN and chess.rodeo runs Stockfish 17 server-side on that exact position, returning the evaluation score, the best move, and the principal variation. You can also open a position directly with a ?fen= URL parameter so the board loads straight into analysis.
If you arrived looking for a public Stockfish FEN API, note that chess.rodeo is a free no-code alternative: it gives you the same engine evaluation and best move for any FEN through the browser, with no key or rate limit.
Analyze King of the Hill and Variant Positions from FEN
You can paste FEN strings from variants such as King of the Hill into the position analyzer to study the resulting middlegame and endgame ideas with engine support.
Analyze Any Chess Position from FEN
FEN (Forsyth-Edwards Notation) describes a full chess position in one line: pieces, side to move, castling rights, en passant square, and move counters.
chess.rodeo does not just display the board. It lets you turn that FEN into a position you can run through Stockfish, review move quality, and continue analyzing from the exact moment that matters.
How to Analyze a FEN Position
- Copy the FEN string — Take the FEN from Chess.com, Lichess, a study board, a puzzle, or your chess software.
- Place it into a PGN header — Use the FEN header shown below. You can add moves after the starting position or leave the PGN short.
- Import it into chess.rodeo — Run Stockfish analysis, inspect best moves, and keep the position as part of your training workflow.
FEN Format Explained
A FEN string has six fields separated by spaces:
- Piece placement — Ranks 8 to 1 separated by slashes. Uppercase is White, lowercase is Black.
- Active color — w means White to move, b means Black to move.
- Castling rights — KQkq lists available castling options. A dash means none remain.
- En passant square — The target square for an en passant capture, or — if it does not apply.
- Halfmove clock — Moves since the last pawn move or capture for the 50-move rule.
- Fullmove number — The current move number in the game.
PGN Template for FEN Analysis
Use this template when you want to analyze a position instead of a full game:
[Event "Position Analysis"]
[Site "chess.rodeo"]
[White "Analysis"]
[Black "Position"]
[FEN "r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 4 4"]
4. Ng5 d5 5. exd5 Na5 *You can keep the move list short or extend it with the line you want to test.
Related Analysis Tools
- PGN Analyzer — Analyze full PGN files and multi-game exports with Stockfish.
- Chess Accuracy Calculator — See how accurate your moves were and compare results by rating.
- Free Chess Analysis — Compare chess.rodeo against Chess.com and Lichess for free analysis.